Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/04—Polysiloxanes
  • C08G77/22—Polysiloxanes containing silicon bound to organic groups containing atoms other than carbon, hydrogen and oxygen
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
  • C07F7/00—Compounds containing elements of Groups 4 or 14 of the Periodic Table
  • C07F7/02—Silicon compounds
  • C07F7/08—Compounds having one or more C—Si linkages
  • C07F7/18—Compounds having one or more C—Si linkages as well as one or more C—O—Si linkages
  • C07F7/1804—Compounds having Si-O-C linkages
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/04—Polysiloxanes
  • C08G77/20—Polysiloxanes containing silicon bound to unsaturated aliphatic groups
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/48—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule in which at least two but not all the silicon atoms are connected by linkages other than oxygen atoms
  • C08G77/58—Metal-containing linkages

Definitions

• the present invention relates to silica (hetero) polycondensates and their use.
• the present invention relates to polycondensates modified with unsaturated organic groups and based on hydrolytically condensable compounds of silicon and optionally other elements.
• Silicic acid (hetero) polycondensates which are modified with organic groups, and processes for their preparation (for example starting from hydrolytically condensable organosilanes by the sol-gel process) are already known in large numbers (see, for example, DE-A-38 35 968 and 40 11 045).
• Such condensates are used for a wide variety of purposes, e.g. as molding compounds, varnishes for coatings, etc. Because of the diverse application possibilities of this class of substances, there is also a constant need to modify the already known condensates, on the one hand to open up new areas of application and on the other hand to further optimize their properties for certain purposes .
• the present invention is therefore based on the object of providing a new class of silica (hetero) polycondensates.
• these new condensates are said to contain a wide variety of variations, especially as regards the nature of the modifying organic groups contained therein.
• Another object of the present invention is a process for the preparation of the above polycondensates, in which one or more hydrolytically condensable compounds of silicon and optionally other elements from the group B, Al, P, Sn, Pb, the transition metals, the lanthanides and the Actinides and / or precondensates derived from the abovementioned compounds, if appropriate in the presence of a catalyst and / or a solvent, hydrolytically condensed by the action of water or moisture, 5 to 100 mol percent, based on monomeric compounds, of the hydrolytically condensable monomers from silanes of the above general Formula (I) can be selected.
• the polycondensates according to the invention are particularly distinguished by the fact that the distance between silicon and the reactive double bond in the silanes of the general formula (I) on which they are based can be set as desired, and these silanes (and thus also the polycondensates) have a plurality of reactive double bonds with the possibility of a three-dimensional one May contain crosslinking and other functional groups which allow a targeted adaptation of the polycondensates according to the invention to the desired field of application.
• the products according to the invention provide a class of polycondensates which can be adapted in a variety of ways to predetermined areas of application and which therefore can be used in all areas in which silica (hetero) polycondensates have already been used, but also open up new uses, for example in the field of optics, electronics, medicine, etc.
• Alkyl residues are e.g. B. straight-chain, branched or cyclic radicals having 1 to 20, preferably 1 to 10 carbon atoms and preferably lower alkyl radicals having 1 to 6, preferably 1 to 4 carbon atoms. Specific examples are methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, isobutyl, n-pentyl, n-hexyl, cyclohexyl, 2-ethylhexyl, dodecyl and octadecyl.
• alkenyl residues are e.g. B. straight-chain, branched or cyclic radicals having 2 to 20, preferably 2 to 10 carbon atoms and preferably lower alkenyl radicals having 2 to 6 carbon atoms, such as vinyl, allyl and 2-butenyl.
• Preferred aryl radicals are phenyl, biphenyl and naphthyl.
• the alkoxy, acyloxy, alkylamino, dialkylamino, alkylcarbonyl, alkoxycarbonyl, arylalkyl, alkylaryl, alkylene, arylene and alkylenearylene radicals are preferably derived from the above-mentioned alkyl and aryl radicals.
• radicals mentioned can optionally carry one or more substituents, for. B. halogen, alkyl, hydroxyalkyl, alkoxy, aryl, aryloxy, alkylcarbonyl, alkoxycarbonyl, furfuryl, tetrahydrofurfuryl, amino, monoalkylamino, dialkylamino, trialkylammonium, amido, hydroxy, formyl, carboxy, mercapto, cyano, nitro, epoxy, SO3H or PO4H2.
• substituents for. B. halogen, alkyl, hydroxyalkyl, alkoxy, aryl, aryloxy, alkylcarbonyl, alkoxycarbonyl, furfuryl, tetrahydrofurfuryl, amino, monoalkylamino, dialkylamino, trialkylammonium, amido, hydroxy, formyl, carboxy, mercapto, cyano, nitro, epoxy, SO3H or PO4H
• halogens fluorine, chlorine and bromine and especially chlorine are preferred.
• the structural unit with the index x is selected from triethoxysilyl, methyldiethoxysilyl, methyldichlorosilyl, 3-methyldimethoxysilyl-propylthio, 3-trimethoxysilyl-propylthio, methyldiethoxysilyl-methylthio and ethoxydimethylsilyl-methylthio.
• B is preferably derived from a substituted or unsubstituted compound B 'having two or more acrylate and / or methacrylate groups (such compounds are referred to below as (meth) acrylates designated).
• the substituents can be selected from the substituents mentioned above.
• Specific examples of such compounds are the following (meth) acrylates:
• Preferred acrylates are e.g. the acrylic acid esters of trimethylolpropane, pentaerythritol and dipentaerythritol. Specific examples of this are trimethylolpropane triacrylate (TMPTA), pentaerythritol triacrylate (PETA), pentaerythritol tetraacrylate and dipentaerythritol pentaacrylate.
• TMPTA trimethylolpropane triacrylate
• PETA pentaerythritol triacrylate
• pentaerythritol tetraacrylate pentaerythritol pentaacrylate.
• preferred (meth) acrylates are those of the formula in which E is H or CH3 and D is an organic group such as z. B. is contained in the above-mentioned special compounds and / or in the compounds described in the following examples.
• C2-C6 alkane diols e.g. ethylene glycol, propylene glycol, butylene glycol, 1,6-hexanediol
• silanes of the general formulas (II) to (IV) are either commercially available or can be prepared by known methods; see. W. Noll, "Chemistry and Technology of Silicones", Verlag Chemie GmbH, Weinheim / Bergstrasse (1968).
• urethane (or urea) structure is formed by silanizing the hydroxyl- (or amino-) substituted starting compound B 'with an isocyanatosilane:
• silanes of the formula (I) prepared as above do not necessarily have to be isolated separately in order to prepare the polycondensates according to the invention. Rather, it is even preferred to first prepare these silanes in a one-pot process and then to condense them hydrolytically, if appropriate after adding further hydrolyzable compounds.
• silanes of the general formula (I) In addition to the silanes of the general formula (I), other hydrolytically condensable compounds of silicon and / or the elements specified above (preferably Al, Ti, Zr, V, B, Sn and / or Pb and particularly preferably Al, Ti, Zr and V) either as such or already in precondensed form for the preparation of the polycondensates according to the invention.
• other hydrolytically condensable compounds of silicon and / or the elements specified above preferably Al, Ti, Zr, V, B, Sn and / or Pb and particularly preferably Al, Ti, Zr and V
• At least 50 mole percent, in particular at least 80 mole percent and especially at least 90 mole percent, based on monomeric compounds, are the silicon compounds of the starting materials used for the preparation of the polycondensates according to the invention.
• the polycondensates according to the invention have at least 10 mole percent, e.g. 25 to 100 mole percent, in particular 50 to 100 mole percent and especially 75 to 100 mole percent, each based on monomeric compounds, on one or more silanes of the general formula (I).
• hydrolytically condensable silicon compounds other than silanes of the general formula (I) which can optionally be used those of the general formula (V) are particularly preferred: X a ' SiR b' (V) in which X and R are as defined above, a 'is an integer from 1 to 4, in particular 2 to 4, and b' is 0, 1, 2 or 3, preferably 0, 1 or 2.
• Particularly preferred compounds of the general formula (V) are those in which the radicals X, which may be the same or different, are selected from halogen (F, Cl, Br and I, in particular Cl and Br), alkoxy (in particular C1 ⁇ 4 -Alkoxy, such as methoxy, ethoxy, n-propoxy, i-propoxy and butoxy), aryloxy (especially C6 ⁇ 10 aryloxy, eg phenoxy), acyloxy (especially C1 ⁇ 4 acyloxy, such as acetoxy and propionyloxy) and hydroxy , the radicals R, which may be the same or different, are selected from alkyl (especially C1 ⁇ 4-alkyl, such as methyl, ethyl, propyl and butyl), alkenyl (especially C2 ⁇ 4-alkenyl, such as vinyl, 1- Propenyl, 2-propenyl and butenyl), alkynyl (especially C2 ⁇ 4-alkynyl, such as
• alkyl radicals also include the corresponding cyclic and aryl substituted radicals, e.g. Cyclohexyl and benzyl, while the alkenyl and alkynyl groups can also be cyclic and the aryl groups mentioned should also include alkaryl groups (such as tolyl and xylyl).
• radicals X hydrogen and alkoxy radicals having 5 to 20, in particular 5 to 10, carbon atoms and halogen- and alkoxy-substituted alkoxy groups (such as, for example, ⁇ -methoxyethoxy) can be mentioned as further suitable groups.
• Further suitable groups R are straight-chain, branched or cyclic alkyl, alkenyl and alkynyl radicals having 5 to 20, in particular 5 to 10 Carbon atoms, such as n-pentyl, n-hexyl, dodecyl and octadecyl, and groups which have epoxy, mercapto or amino residues.
• residues X are not present in the end product, but are lost by hydrolysis, the hydrolysis product generally also having to be removed sooner or later in any suitable manner, residues X which do not carry any substituents and give low molecular weight hydrolysis products are particularly preferred.
• residues X which do not carry any substituents and give low molecular weight hydrolysis products are particularly preferred.
• lower alcohols such as methanol, ethanol, propanol, n-, i-, sec- and tert-butanol.
• the compounds of the formulas (I) and (V) can be used in whole or in part in the form of precondensates, i.e. Compounds which are formed by partial hydrolysis of the compounds of the formulas (I) and (V), either alone or in a mixture with other hydrolyzable compounds, as are described in more detail below.
• Such oligomers which are preferably soluble in the reaction medium, can be straight-chain or cyclic, low-molecular partial condensates (polyorganosiloxanes) with a degree of condensation of e.g. about 2 to 100 (e.g. 2 to 20), especially about 6 to 10.
• silanes can be produced by known methods; compare W. Noll, op. cit.
• the ratio of the silicon compounds with four, three, two or a hydrolyzable radical X (or else the hydrolyzable compounds different from silicon compounds) to one another depends primarily on the desired properties of the resulting polycondensate or of the end product produced therefrom.
• hydrolyzable aluminum compounds optionally used for the preparation of the polycondensates, those which have the general formula (VI) are particularly preferred: AlX'3 (VI) in which the radicals X ', which may be the same or different, are selected from halogen, alkoxy, alkoxycarbonyl and hydroxy.
• X ' which may be the same or different, are selected from halogen, alkoxy, alkoxycarbonyl and hydroxy.
• chelate ligands for example acetylacetone or acetoacetic acid ester, acetic acid).
• Aluminum alkoxides and halides are particularly preferred aluminum compounds.
• concrete examples can be mentioned Al (OCH3) 3, Al (OC2H5) 3, Al (On-C3H7) 3, Al (Oi-C3H7) 3, Al (OC4H9) 3, Al (Oi-C4H9) 3, Al (O-sek-C4H9) 3, AlCl3, AlCl (OH) 2
• Suitable hydrolyzable titanium and zirconium compounds which can be used according to the invention are those of the general formula (VII): MX a ' R b' (VII) in which M denotes Ti or Zr and X, R, a 'and b' are as defined in the case of the general formula (V). This also applies to the preferred meanings of X and R.
• the compounds are particularly preferred of formula (VII) those in which a 'is 4.
• complexed Ti and Zr compounds can also be used.
• Additional preferred complexing agents are acrylic acid and methacrylic acid.
• zirconium and titanium compounds which can be used according to the invention are the following: TiCl4, Ti (OC2H5) 4, Ti (OC3H7) 4, Ti (Oi-C3H7) 4, Ti (OC4H9) 4, Ti (2-ethylhexoxy) 4; ZrCl4, Zr (OC2H5) 4, Zr (OC3H7) 4, Zr (Oi-C3H7) 4, Zr (OC4H9) 4, ZrOCl2, Zr (2-ethylhexoxy) 4
• hydrolyzable compounds which can be used to prepare the polycondensates according to the invention are e.g. Boron trihalides and boric acid esters (such as BCl3, B (OCH3) 3 and B (OC2H5) 3), tin tetrahalides and tin tetraalkoxides (such as SnCl4 and Sn (OCH3) 4) and vanadyl compounds such as e.g. VOCl3 and VO (OCH3) 3.
• Boron trihalides and boric acid esters such as BCl3, B (OCH3) 3 and B (OC2H5) 3
• tin tetrahalides and tin tetraalkoxides such as SnCl4 and Sn (OCH3)
• vanadyl compounds such as e.g. VOCl3 and VO (OCH3) 3.
• the silanes of the general formula (I) are hydrolyzed and polycondensed, if appropriate with the addition of other cocondensable components.
• the polycondensation is preferably carried out by the sol-gel process, as it is e.g. is described in DE-A-27 58 414, 27 58 415, 30 11 761, 38 26 715 and 38 35 968 and is explained in more detail below.
• the polycondensates according to the invention can optionally be polymerized with the addition of other copolymerizable components (see below).
• the polymerization can be carried out, for example, thermally or photochemically using methods as described in DE-A-31 43 820, 38 26 715 and 38 35 968 are described and are also explained in more detail below.
• the polycondensates according to the invention can be produced in a manner customary in this field. If silicon compounds are used practically exclusively, the hydrolytic condensation can in most cases take place by adding the stoichiometrically required amount of water or, if appropriate, an excess of water at room temperature to the silicon compounds to be hydrolyzed, which are present either as such or dissolved in a suitable solvent or directly with gentle cooling (preferably with stirring and in the presence of a hydrolysis and condensation catalyst) and the resulting mixture is then stirred for some time (one to several hours). In the presence of the more reactive compounds of Al, Ti and Zr, it is generally advisable to gradually add the water.
• the hydrolysis is generally carried out at temperatures between -20 and 130 ° C, preferably between 0 ° C and 30 ° C or the boiling point of the solvent which may be used.
• the best way of adding water depends primarily on the reactivity of the starting compounds used.
• the dissolved starting compounds can be slowly added dropwise to an excess of water, or water can be added in one portion or in portions to the starting compounds, which may be dissolved. It can also be useful not to add the water as such, but with it With the help of water-containing organic or inorganic systems in the reaction system.
• water in the reaction mixture with the aid of moisture-laden adsorbents, for example molecular sieves, and water-containing organic solvents, for example 80% ethanol.
• moisture-laden adsorbents for example molecular sieves
• water-containing organic solvents for example 80% ethanol.
• the water can also be added via a reaction in which water is formed, for example in the formation of esters from acid and alcohol.
• ketones preferably lower dialkyl ketones such as acetone and methyl isobutyl ketone
• ethers preferably lower dialkyl ethers such as diethyl ether and dibutyl ether, THF, amides, esters, in particular ethyl acetate, dimethylformamide , and their mixtures in question.
• Proton-releasing compounds are not necessarily, but are preferably used, hydrolysis and condensation catalysts.
• Examples include organic and inorganic acids such as hydrochloric acid, formic acid and acetic acid, with hydrochloric acid being particularly preferred as the catalyst.
• suitable catalysts are e.g. NH3, NaOH or KOH.
• Catalysis with fluoride ions is also possible, e.g. using HF, KF or NH4F.
• the starting compounds do not necessarily all have to be present at the start of the hydrolysis (polycondensation), but in certain cases it can even prove advantageous if only some of these compounds are first brought into contact with water and the remaining compounds are added later.
• water in several stages, e.g. in three stages.
• the first stage e.g. one tenth to one twentieth of the amount of water stoichiometrically required for the hydrolysis is added.
• a fifth to a tenth of the stoichiometric amount of water is added, and after further brief stirring, a stoichiometric amount of water is finally added, so that at the end there is a slight excess of water.
• the condensation time depends on the respective starting components and their proportions, the catalyst used, the reaction temperature, etc. In general, the polycondensation takes place at normal pressure, but it can also be carried out at elevated or reduced pressure.
• the polycondensate obtained in this way can be further processed either as such or after partial or almost complete removal of the solvent used or of the solvent formed during the reaction. In some cases it may prove advantageous to replace the excess water and the solvent formed and, if appropriate, additionally used in the product obtained after the polycondensation with another solvent in order to stabilize the polycondensate.
• the reaction mixture can be thickened, for example in vacuo at a slightly elevated temperature (up to a maximum of 80 ° C.), so that it can still be taken up with another solvent without any problems.
• the polycondensates according to the invention are to be used as coatings for the coating (for example of plastics such as PVC, polycarbonate, polymethyl methacrylate, polyethylene, polystyrene etc., of glass, paper, wood, ceramic, metal etc.), these can be used at the latest before use if necessary, customary paint additives are added, such as, for example Colorants (pigments and dyes), fillers, oxidation inhibitors, leveling agents, UV absorbers, stabilizers and the like. Additives to increase conductivity (e.g. graphite powder, silver powder etc.) also deserve mention in this context. In the case of use as a molding compound, the addition of inorganic and / or organic fillers, such as e.g. (Glass) fibers, minerals etc.
• inorganic and / or organic fillers such as e.g. (Glass) fibers, minerals etc.
• a suitable initiator can be added.
• photoinitiators e.g. which are used commercially available. Examples include Irgacure 184 (1-hydroxycyclohexylphenyl ketone), Irgacure 500 (1-hydroxycyclohexylphenyl ketone, benzophenone) and other photo initiators of the Irgacure type available from Ciba-Geigy; Darocur 1173, 1116, 1398, 1174 and 1020 (available from Merck), benzophenone, 2-chlorothioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, benzoin, 4,4'-dimethoxybenzoin, benzoin ethyl ether, benzoin isopropyl ether, benzyl dimethyl ketal, 1.1 , 1-trichloroacetophenone, diethoxyacetophenone, dibenzosuberone and camphorquinone.
• the latter initiator is particularly suitable when exposed to light
• organic peroxides in the form of diacyl peroxides, peroxydicarbonates, Alkyl peresters, dialkyl peroxides, perketals, ketone peroxides and alkyl hydroperoxides in question.
• thermal initiators are dibenzoyl peroxide, tert-butyl perbenzoate and azobisisobutyronitrile.
• the initiator can be added in customary amounts.
• a mixture containing 30 to 50% by weight solid (polycondensate) initiator in an amount of e.g. 0.5 to 5 percent by weight, in particular 1 to 3 percent by weight, based on the mixture, can be added.
• a lacquer optionally provided with a photoinitiator, based on polycondensates according to the invention can then be applied to a suitable substrate.
• Conventional coating methods can be used for this coating, e.g. Diving, flooding, pouring, spinning, rolling, spraying, painting, electrostatic spraying and electrocoating.
• the lacquer does not necessarily have to contain solvents. In particular when using starting substances (silanes) with two alkoxy groups on the Si atom, it is also possible to work without the addition of solvents.
• the applied varnish is preferably allowed to dry before curing. Then, depending on the type or presence of an initiator, it can be thermally or by irradiation (for example with a UV lamp, a laser, an electron beam, a light source which emits radiation in the visible range, etc.) in a manner known per se be hardened. Combinations of curing methods are of course also possible, for example UV / IR or UV / thermal.
• the hardening of the applied lacquer by irradiation in the presence of a photoinitiator is particularly preferred.
• epoxy groups in particular respond better to thermal treatment than to radiation treatment.
• unsaturated groups are already present in the polycondensates according to the invention (at least those which are derived from the radical B), it can prove advantageous in certain cases to add further compounds (preferably purely organic) to the products according to the invention before or during their further processing (curing) Nature) with unsaturated groups.
• Preferred examples of such compounds are compounds B ', (meth) acrylic acid and compounds derived therefrom, in particular (meth) acrylic acid esters of (preferably monohydric) alcohols (e.g. C1 ⁇ 4-alkanols), (meth) acrylonitrile, styrene and mixtures thereof. If the polycondensates according to the invention are used to produce a coating varnish, such compounds can simultaneously act as solutions or diluents.
• the production of moldings based on the polycondensates or molding compositions according to the invention can be carried out using any of the methods customary in this field, for example by injection molding, molding, extrusion, etc.
• the products according to the invention are also suitable for the production of composite materials (for example with glass fiber reinforcement).
• the polycondensates according to the invention are highly reactive systems which, for. B. cure with UV radiation within fractions of a second to mechanically stable coatings.
• the hardening to form bodies can also take place in the range from a few seconds to minutes.
• the distance between silicon and functional organic group i.e.
• the mechanical (e.g. flexibility, scratch and abrasion resistance) and physicochemical properties (adsorption, color, absorption behavior, refractive index, adhesion, wetting behavior etc.) of the chain can be determined via the chain length and the presence of further functional groups in this chain (End) products are influenced.
• hydrolyzable groups e.g. alkoxy groups
• end products produced therefrom e.g. Silicon or glass-like properties can be set.
• the polycondensates according to the invention are suitable, for. B. for use as or in coating, filler or bulk materials, adhesives (s), adhesion promoter (s), sealing compounds and injection molding compounds.
• Coatings and moldings made from the polycondensates according to the invention have the advantage that they can be structured photochemically (see, for example, DE-A-38 35 968).
• Special areas of application are e.g. B. the coating of substrates made of metal, Plastic, paper, ceramics, wood, glass, textiles etc. by dipping, pouring, painting, spraying, electrostatic spraying, electrocoating etc. and the use of optical, optoelectric or electronic components.
• the possible use for the production of scratch-resistant, abrasion-resistant and / or corrosion protection coatings also deserves mention in this context.
• acrylate J 0.1 mol (29.5 g, 26.6 ml) of acrylate J in 100 ml of solvent (e.g. ethanol, benzene, cyclohexane, diethyl ether or methyl tert-butyl ether) with 0.1 mol (16.5 g, 18.8 ml) of silane V.
• solvent e.g. ethanol, benzene, cyclohexane, diethyl ether or methyl tert-butyl ether
• 0.15 mol (44.45 g) of acrylate J are placed under cooling in a water bath at 20 ° C. under nitrogen protection and quickly with 0.15 mol (27.05 g) of silane I and 0.0015 mol (0.0842 g ) KOH in 6 g of ethanol.
• the reaction mixture is stirred for 5 minutes (iodine-mercaptan test), then taken up in 200 ml of diethyl ether and shaken out and washed with 20 ml of H2O until the wash water has a neutral reaction.
• the ether phase is e.g. B. dried over Na2SO4 or with a hydrophobic filter and concentrated in a water jet vacuum at 35-40 ° C. The residue is then dried under high vacuum at 35-40 ° C. for about 1 hour.
• the preparation is carried out as in Preparation Example 2 using an equimolar amount of silane III instead of silane I.
• the preparation is carried out as in preparation example 3 using an equimolar amount of acrylate L instead of acrylate J.
• the polycondensate solution obtained in Example 3 is mixed with 5 percent by weight, based on the polycondensate, of a UV initiator (Irgacure (R) 907) and then applied to a plate made of polymethyl methacrylate using a film-drawing slide. The resulting coating is then cured by UV radiation (lamp output 2000 W). The curing times, the layer thicknesses of the hardened coatings and the abrasion after 100 cycles with the Taber abraser are given in Table 1 below. As can be seen from the above results, the polycondensates according to the invention can be hardened by radiation in a fraction of a second to give protective coatings with considerable abrasion resistance. Of course, even longer coatings can be obtained through longer irradiation times and / or other suitable measures (increasing the amount of initiator or the emitter output).
• Example 2 The practically solvent-free polycondensate from Example 2 is applied to a glass plate after the addition of a UV initiator using a doctor blade and cured by UV radiation (lamp output 2000 W).
• the following table 2 summarizes the type and amount of UV initiator, the irradiation times, the resulting layer thicknesses and the abrasion values after 100 cycles (Taber abrasives).
• the polycondensate used is particularly characterized in that it is highly elastic and shows a "self-healing" effect (ie cracks flow again).
• E-module of the coatings approx. 2150 MPa
• the abrasion was determined after 100 cycles with the Taber abraser for polycarbonate and PVC to 28 and 37%.
• a polycondensate prepared in practically solvent-free form according to the processes described in the examples above is mixed with 0.5% by weight Irgacure (R) 184 (UV initiator), placed in a hardening mold (diameter 4 cm) and with a capacity of 500 or 1000 W (medium pressure mercury lamp Loctite Uvaloc (R) 1000) irradiated for approx. 1 minute from the front and the back.
• R UV initiator
• Similar results are obtained by thermal curing at 60 to 70 ° C. for about one hour after addition of 0.5 to 1.0 percent by weight of t-butyl perneodecanoate.
• Table 5 shows the refractive indices (n D ) and the Abbe numbers ( D ) of some of the moldings produced in this way (UV curing).
• UV-hardened cuboid rods were produced.
• the elastic modulus was determined on these rods in a 3-point bending test (universal testing machine UTS-100). The values obtained are summarized in Table 6 below. A range of values is sometimes specified. The exact value then depends on the exact curing conditions.

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• 1990
  • 1990-04-05 DE DE4011044A patent/DE4011044A1/de active Granted
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